Despite the many advances that have been made to modern rifle design, muzzle loading rifles remain popular with firearms enthusiasts. The basic loading sequence for a muzzle loading rifle has not changed significantly since its inception. First, a quantity of black powder is poured into the barrel. Second, a wad, comprised of either cloth or leather, is pushed down the barrel and tapped against the black powder with a long rod to compact the powder. Third, a lead ball is pushed down the barrel in contact and on top of the wad.
The introduction of rifling into muzzle loader design greatly increased its accuracy. The benefits of imparting a spinning motion to any firearm projectile are well known. However, these benefits in a muzzle loader were offset partially by increased difficulties with loading. Projectiles had to be slightly oversized compared to gun barrel land-to-land diameter in order to ensure engagement with the barrel rifling. Even though projectiles were and are typically made of soft lead, it became very difficult to push the projectile down the barrel. In fact, the amount of force necessary to push the projectile down the barrel could sometimes deform the projectile causing erratic and therefore inaccurate flight.
Sabots address some of the above-described problems by providing a protective surface along the perimeter or sides of the projectile, which contacts with the rifle barrel during loading. Typically, sabots are slightly oversized with respect to the land-to-land inside diameter of a rifled gun barrel. Thus, the sabot exterior engages the barrel rifling, thus creating a stabilizing spinning motion to the projectile as it exits the firearm. Using a sabot also eliminates the use of the wad, since the sabot's closed base provides a seal for the gases generated during firing. After firing, the sabot is intended to quickly peel away from the projectile.
However, prior art sabot designs, for both military and civilian applications, have not adequately addressed loading problems, or taken advantage of improved design methods to ensure that the sabot effectively breaks free of the projectile after firing in order to not interfere with the projectile flight path. There remains a need for a sabot which is relatively easy to load, and that provides improved protection for projectiles, particularly those made of soft metal. Moreover, there remains a need for such a sabot which quickly clears the path of a projectile as it exits a firearm barrel without adversely affecting firearm accuracy.